We present the first quantitative GIS-based flood inundation analysis using terrain data extracted from a commercial video game, applied to the fictional city of Los Santos from Grand Theft Auto V (GTA V) under two contrasting IPCC Fifth Assessment Report (AR5) Representative Concentration Pathway (RCP) scenarios (RCP 2.6, strong mitigation, and RCP 8.5, high-emission baseline) combined with historical storm surge records from the Los Angeles tide gauge, across three time horizons (2100, 2300, and 2500). Los Santos serves as an ideal case study because it faithfully replicates Los Angeles (LA), enabling direct comparison of simulated flood outcomes in the game world with published scientific vulnerability analyses for LA. Results indicate that Los Santos is modelled with sufficient geomorphological detail for projected flooding patterns to closely resemble those identified for Los Angeles, including the spatial sequence of inundation across the marina district, the Pacific Palisades coastline, and the port. Under RCP 8.5 conditions with storm surges, combined sea levels of up to 5.18 m by 2300 would inundate 5.1 % of the mapped land area; in a longer-term illustrative projection to 2500, extreme sea levels of 8.22 m would inundate 6.5 %, rendering the port, wastewater infrastructure, and coastal energy facilities permanently non-functional. The mitigation scenario RCP 2.6 limits inundation to 2.2 % of land area at 2300 with no major infrastructure at risk. We evaluate the potential of this approach for geoscience communication and education, arguing that the intrinsic familiarity of the Los Santos environment provides an affective engagement with climate change impacts that is difficult to achieve through conventional visualisation alone.